Field of the Invention
The invention relates in general to a touch control device and method and a method for forming a touch control device, and more particularly to a touch control device and method and a method for forming a touch control device capable of preventing false positives.
Description of the Related Art
In response to user requirements and progressing technologies, touch control technologies are extensively applied to electronic products. In general, a touch control module of touch control technologies, from top to bottom, includes a glass layer (or referred to as a protection layer), a sensing layer and a support layer. The support layer, usually made of a metal material (e.g., iron), is electrically connected to a ground potential, and has an area greater than that of the sensing layer to fulfill a support effect. In other words, as the length and width of the support layer are respectively greater than the length and width of the sensing layer, a gap is preserved between an edge of the support layer and an edge of the sensing layer. However, due to the above structure, power lines emitted from sensing units at edges of the sensing layer may penetrate through the gap to connect to the support layer via a non-normal touch object on the glass layer, resulting in a false positive. For example, when water drops or other splashed liquids are located near positions of the gap on the glass layer, the power lines of nearby sensing units may form an electrical connection of different potentials with the grounded support layer sequentially through the glass layer, the water drops or liquids, the glass layer and the gap. As such, the sensing units are caused to generate a potential change that may further trigger a false positive of a touch point.
In some conventional solutions, an electrostatic discharge (ESD) circuit is disposed in the gap between an edge of the support layer and an edge of the sensing layer. Since the ESD circuit is similarly electrically connected to a ground potential or a predetermined constant potential, an electrical connection of different potentials may still be formed with the sensing layer to lead to a false detecting results.